:root {
    --primary-color: #0056b3;
    --secondary-color: #218838;
    --background-color: #f4f4f4;
    --text-color: #111111;
    --accent-color: #138496;
    --link-color: #004085;
    --light-bg: #e0e0e0;
}

body {
    font-family: 'Poppins', Arial, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    padding: 0;
    line-height: 1.6;
    text-rendering: optimizeLegibility;
}

section h1, article h1, nav h1, aside h1 {
  font-size: 2.5rem; 
  font-weight: bold;
  line-height: 1.2;
  margin-bottom: .5rem;
  min-height: 1.2em;
}

.section-title {
    text-align: center;
    font-size: 2em;
    font-weight: bold;
    color: var(--text-color);
    margin-bottom: 20px;
    min-height: 1.5em;
}

a {
    color: var(--link-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: var(--primary-color);
}

main {
    padding-top: 0;
    display: block;
}

.navbar-dark {
    background-color: var(--primary-color);
    padding: 15px 0;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
    min-height: 74px;
    contain: layout;
}

.navbar-brand {
    font-size: 1.25rem;
    font-weight: bold;
    color: white;
    min-width: 135px;
    display: inline-flex;
    align-items: center;
}

footer {
    background-color: var(--primary-color);
    color: white;
    padding: 30px 0;
    text-align: center;
    font-size: 1em;
    width: 100%;
    contain: content;
}

.welcome {
    background-color: var(--primary-color);
    color: white;
    padding: 50px 20px;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
    text-align: center;
    min-height: 200px;
}

.webchat-box {
    background: white;
    border: 2px solid #bbb;
    padding: 25px;
    width: 90%;
    max-width: 440px;
    border-radius: 12px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.25);
    text-align: center;
    margin: 30px auto;
    min-height: 310px;
    contain: layout;
}

.iframe-container {
    width: 100%;
    height: 300px;
    background-color: #f0f0f0; 
    aspect-ratio: 16 / 9;
}

.btn {
    border-radius: 30px;
    font-size: 1.2em;
    padding: 15px 10px;
    min-height: 50px;
    min-width: 150px;
    transition: transform 0.2s ease, background 0.3s ease;
    text-transform: uppercase;
    font-weight: bold;
    background: var(--secondary-color);
    color: white;
    border: none;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

@media (max-width: 768px) {
    .navbar-brand { font-size: 1.1rem; min-width: 110px; }
    .chat-content { padding: 20px; width: 100%; min-height: 300px; }
}